Add Response With JSON Regardless Of Content Type as a Rails TIL

rails/respond-with-json-regardless-of-content-type.md

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+# Respond With JSON Regardless Of Content Type
+
+Let's say you want to serve some JSON from an endpoint (for example, you might
+be serving the `apple-app-site-association` file for iOS Universal Links).
+Regardless of whether the endpoint is requested as JSON (`application/json`),
+HTML (`text/html`), or something else (`plain/text`), you want to respond with
+JSON.
+
+The [`format#any`
+method](https://api.rubyonrails.org/classes/ActionController/MimeResponds.html)
+can be used when defining the `respond_to` block. This tells the controller
+that _any_ mimetype is accepted.
+
+```ruby
+def show
+  respond_to do |format|
+    format.any do
+      render params[:page],
+        formats: 'json',
+        content_type: "application/json",
+        layout: false
+    end
+  end
+end
+```
+
+The other important element in this is `formats: 'json'` which helps Rails find
+your `<template_name>.json.erb` file in the `views` directory.
+
+Though I cannot find any documentation for it, `format.all` appears to work the
+same as `format.any` as described in the above example.
+
+h/t Dillon Hafer